In recent years, non-volatile memories that are data-rewritable semiconductor devices are widely used. In general, memory cells are subjected to reading operation, write operation and erase operation. During erase operation, some memory cells may be over-erased, which may need to be recovered by later soft-programming operation. But before soft-programming operation, power may be abnormal loss and therefore the over-erase memory cells are not recovered. Data reading from the memory may be incorrect due to background current leakage by the over-erased memory cells.
Therefore, how to recover background leakage from over-erased memory cells due to abnormal power loss is disclosed in the application.